LL-9033 Handle inner exception after pairing timeout

[juan-cortes]

🦒 Context (issues, jira)

https://ledgerhq.atlassian.net/browse/LL-9033

💻 Description

This is a bit of a pickle, for context the new fw 2.0.2 introduced some changes to the new characteristic, the one that brought the performance boost 13d63400-2c97-0004-0003-4c6564676572, which threw an error from inside the monitor characteristic call from ble-plx.

We have to note that this is only when we reach the 30s timeout when the pairing code is shown. You need to be pairing a new device, ignore the pairing prompt, and reach this crash. If you feel this change introduces a performance hit (I measured and looked heavily into the instanceof perf and it seems pretty light) please advice for a better solution. I banged my head for two days and this is the only solution I could find that doesn't totally silence the error or hinder the functionality.

As an explanation of why this is happening, my understanding is that when we create the observable outside of the transport instance or the open method, the exception thrown is unhandled and therefor breaks the application. By catching that specific error in the observable, channeling it into the inferMTU method, and rethrowing it from there, we get the handled error and the correct "Pairing Failed" screen instead of an app crash.

In other words, without this, the error is unhandled.

[codecov]

Codecov Report

Merging #778 (98de152) into master (84b9178) will decrease coverage by 0.07%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #778      +/-   ##
==========================================
- Coverage   45.17%   45.09%   -0.08%     
==========================================
  Files          83       83              
  Lines        5052     5060       +8     
  Branches      893      897       +4     
==========================================
  Hits         2282     2282              
- Misses       2570     2576       +6     
- Partials      200      202       +2     

Impacted Files	Coverage Δ
.../react-native-hw-transport-ble/src/BleTransport.ts	0.00% <0.00%> (ø)

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[juan-cortes]

Think we can merge this until we figure out a cleaner solution @gre it addresses two bugs for 2.0.2
I don't think we can solve the typing issue without introducing checking overhead to make TS happy, we'd have to check that it's a Buffer and not an error every time.

https://ledgerhq.atlassian.net/browse/LIVE-1400
https://ledgerhq.atlassian.net/browse/LIVE-579